I’m not allowed more than one image in a post as I’m a new user, I hope imgur links are fine? let me know if you want the pictures some other way.

Here are pictures of the (rather shitty) soldering. I know the pi looks like a graveyard, but I have lit an led from every power/output and to every ground pin, so I don’t think that’s an issue.
I also know that soldered the pins the wrong way around, and so the pHat won’t sit over the board, but I am plugging it in the right way so the pins match up.
I did put the pHat on the wrong way around the first time (pins 1 and 2 into 40 and 39 respectively and so on) - is it possible that I damaged it?

You should definitely go over each solder joint again. Don’t add any more solder just yet, but heat the joint gently until the solder thats there melts and flows into the hole and covers as much of the little copper ring around each pin as possible.

Solder joints should be little cones, with the backside of the pin poking up.

yeah they are backwards, that will teach me to rush stuff :(
and er… yes …
I put the pins in the wrong way, and thought it would be ok because I turned it over… but now I think about it its not ok.
I’m going to try and redo all the soldering on the pHat - hopefully it will work then.

Thanks for everyone’s help! - much appreciated.

Edit: Thanks for the video Gagetoid - ill certainly give that a watch.

Yeah I came to that realization as i read major_tomm’s post - I just hadn’t thought it through as I was doing it. I was going to try and remove the solder - but decided the time I would spend doing it badly wasn’t worth it and ordered a new pHat. Maybe one day when i’m more competent i’ll rescue this one - but i thought it would be best to get it working properly and neatly the first time.

Got my new phat and everything works great - thanks to everyone for suggestions, but it was just me being stupid in the end.
I managed to unsolder(?) the other one using some solder wick as well - the board looks a bit messy but it works :)

not sure if you “close” or “solve” threads on these forums or just leave them? I cant see an option but feel free to close it if that’s wagwan.